| Abstract
| - By using a combination of transmission electron microscopy (TEM) and scanning transmission electronmicroscopy (STEM) techniques, we have followed in detail the structural and chemical changes occurring onthe very surface layers of powder CexPr1-xO2 mixed oxides, used as supports, during the preparation of rhodium-supported catalyst by wet impregnation techniques. Results demonstrate the occurrence of Pr3+ leaching outof the Ce−Pr solid solution during the impregnation step, which promotes a severe spatial redistribution oflanthanide cations at the surface of the mixed oxide. A highly heterogeneous surface composition is reachedafter the metal deposition. Mobilization of the support also affects the features of the final surface structureof the metal-supported nanoparticles, which become decorated by patches of support material. All these factsseem crucial to properly understand the redox and catalytic behavior of this kind of materials.
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